This invention relates to sprinklers and particularly high-volume, part-circle sprinklers used in agricultural irrigation.
Sprinkler heads of the high-capacity type of interest in this application are disclosed, for example, in the following U.S. Pat. Nos. 2,649,268; 3,559,887; 3,580,507; 3,592,388; 3,623,666; 3,744,720; and 3,986,671. It is characteristic of all these sprinkler heads that they include a stationary annular housing which is in fluid communication with a source of water under pressure, with a rotating sprinkler body assembly mounted on the stationary housing assembly for rotation about a generally vertically extending axis. Typically, the sprinkler head includes a barrel that is movable back-and-forth by means of a fairly complex mechanical arrangement, within a defined arc set by adjustable stops. Some sprinkler heads of this type also incorporate a pulse arm that moves into and out of the stream emitted by the nozzle. The pulse arm is generally driven in one direction by the emitted stream and in the appropriate direction by a spring or the like. Interruption of the stream tends to even out the sprinkler pattern.
There remains a need for a high-volume sprinkler having a simple, reliable and cost-effective mechanism for enabling automatic reversal of the direction of rotation of the sprinkler head through easily adjustable, part-circle arcs of rotation.
In one exemplary but nonlimiting embodiment, there is disclosed and described herein a high-volume sprinkler head comprising a barrel having a nozzle at one end thereof, the barrel having a fixed portion and a relatively movable portion adapted for pivoting movement relative to the fixed portion. The barrel is mounted on an annular upper support base rotatably supported on a lower stationary base for rotation in opposite directions through an arc, about a substantially vertical axis. A fluid-operated actuator is arranged to pivot the relatively movable portion of the barrel relative to the fixed portion of the barrel between predetermined first and second reaction angles that cause the barrel and the annular upper support base to rotate in opposite directions, about the substantially vertical axis, respectively, when a stream is emitted from the nozzle. First and second magnets (or “stops”) are supported at circumferentially-spaced locations about an edge of the lower stationary base, the pair of magnets having reverse polarities. A magnetic valve is mounted on the upper support base in fluid communication with the actuator, and the magnetic valve is adapted to align with the first magnet upon rotation of the barrel and the annular upper support base in one of the two opposite directions, and to align with the second magnet upon rotation of the barrel and the annular upper support base the other of the opposite directions. The magnetic valve, under influence of the first and second magnets, is operative, respectively, to supply fluid under pressure to the fluid-operated actuator to cause the relatively movable portion of the barrel to pivot to the first predetermined reaction angle, and to drain fluid from the fluid-operated actuator to cause the relatively movable portion of the barrel to pivot to the second predetermined reaction angle.
It is another feature of the exemplary embodiment that the first and second magnets are adjustable along the edge of the lower stationary base to thereby enable adjustment of the arc.
It is another feature of the exemplary embodiment that the fluid-operated actuator incorporates a spring that causes the cylinder to retract to thereby move the relatively movable portion of the barrel to said second predetermined reaction angle.
When fluid is drained from the fluid-operated actuator, a spring causes the cylinder to retract to thereby move the relatively movable portion of the barrel to the second predetermined reaction angle.
It is another feature that the fixed portion and the relatively movable portion of the barrel are connected by a ball joint, an upper component of the ball joint provided on the relatively movable portion of the barrel and a lower component of the ball joint provided on the relatively fixed portion of the barrel. A pair of oppositely extending pivot pins are provided on the upper component of the ball joint, the pivot pins received in respective brackets secured to the fixed portion of the barrel.
It is another feature that adjustment screws are arranged to engage the upper component of the ball joint to enable adjustment of the pivoting movement of the fixed portion of the barrel relative to the relatively movable portion of the barrel, thereby enabling adjustment of the first and second reaction angles.
It is another feature that the sprinkler head is provided with a stream interrupter rod having a distal end movable into and out of the stream emitted from said nozzle.
It is another feature of an alternative embodiment that the magnetic valve and magnets be omitted in favor of a three-way mechanical toggle valve in combination with mechanical stops.
Still other features, advantages and benefits of the exemplary embodiment will become apparent from the detailed description that follows in connection with the drawings identified below.